FlatCam [1]} replaces the lens system by a coded amplitude mask close to the sensor. For ease of calibration, this mask is designed to be separable, i.e., it can be written as an outer product of 2 one dimensional patterns. Neglecting the diffraction effects, it was shown in [1]} that using such a mask, the \(m \times m\)  measurements \(\mathbf {Y}\)  obtained on the FlatCam sensor can be written as
\(\mathbf {Y}= \mathbf {\Phi _L} \mathbf {X}\mathbf {\Phi _R}^T\) 
